Secondary battery or accumulator



Patented Mar. 20, 1928. I Q

nnnunno ammma sum or MADRID, sum, nssrenon enema-w 'ro MANUEL comm n1 IIEBES, OI KIEBESDEL GAMING, ABTUBIAS, SPAIN.

SECONDARY BATTERY OR ACCUMULATOR;

Io Drawing.

- the solution of the arduous problem t elec-- 1ts conductivity and -make,

' charge on the trical generation is deposited on the negative pole.

and accumulation.

The negative electrode of this system is of metallic zinc; the positive electrode is formed essentially of silver finely pulverized, either in the form of dust imprisoned within meshes of the same metal, or else as a porous coating of silver precipitated chemically or by galvanostegy on an unattachable body, such as asbestos or, better, graphite. The third element which specially characterizes this new system of accumulators is its electrolyte, which consists of an aqueous solution of chloride of zinc mixed with another halogenous salt, or salts, of the same metal, and to which should be added a small roportion of chlorhydric acid, to increase more adhesive the deposit of zinc precipitated during the negative 'pole. The halogenous salts mixed with the chloride of zinc should be bromide, iodide or some other of less chemical heat of formation than that of the chloride. Let us suppose, for greater simplicity and as the most practical case, that the salt mixed with the chloride is bromide ofzinc.

On charging an element of this system the bromide commences by decomposing, the bromine unites with the silver, and

During this phase of the charge the electrosmotive power is one volt. When the bromide begins to get exhausted the decomposition. of the chloride commences. The chlorine forms chlorides of silver and dislodges the bromine, which in part remains occluded and in part remains in dissolution or recipitated in the bath. So that the ch'lori e of zinc and the bromides of silver are decom osed, the tension rises rapidly to two vo ts. When all the bromine has been dislodged, and the silver completely chlorinized, the third and last phase of the charge appears; the chlorine reacts with the bromine, forms chlorides with it, and remains mixed with it in the electrolytic bath, causing the electro-motive power to rise and remain at two volts and two tenths. When all the bromine is charge, and is, besides,

the zinc- Appllcation Med December 14, 1925. Serial No. 75,432.

saturated .with chlorine, and the latter commences to bubble visibly round the ositive pole, the charge has finished and t e voltage cont nues at two and two-tenths.

The d scharge of the accumulatoris absolutely identical, but is efiected in inverted order. It presents a first and prolonged phase during which the tension is maintamed at two volts and two-tenths, chloride of zinc being formed at the expense of the chlorine united to the bromine. Afterwards the chlorine of the chlorides of silver commenoes to come into action, and this in its turn 15 replaced by the bromine, the tension falling to two volts. Finally, bromide of 'zinc is formed, the bromine of the bath becoming exhausted and the bromides of silver decomposing.

The superiority of this system is shown, above all, n what refers to its electro-mot ve powerythe latter is maintained practlcally equal in the charge and in the dissuperior to the tension of the usual systems. To this elevated electro-motive power is united a specific capacity which can pass practically the half' kllowatt-hour per kilogram, and which places th1s system of accumulators far above all the s stems hitherto conceived or em ployed. o r besides .the fact that the bromine or iodine can accumulate to an'unlim- 1ted extent, either in solution or preci itated, and besides the fact that the chlorine produces an equilibrium with the water and the othenhalogens by means of which it is retained 1n a very elevated proportion, the silver in a state of extreme pulverization and as anode has the property of absorbing practically unlimited quantities of the halogens, which on being occluded in it produce an ascendingseries of fixed reactions, followed by solid solutions with progressive duce parasitic reactions in an open circuit,

it is advisable to surround the negative electrodes with a diaphragm, which may be of asbestos impregnated with cement or simply artificial parchment. Finally, we would observe that not all the active elements necessary for the work- 1 ing of the accumulator remain immovable on the electrodes, where on the other hand they must necwsarily operate; art of the halogens se arate themselves rom the positive ole. this system there is 'ven to that sic problem an original so ution which opens a new horizon: all the active elements do not remain adhering to the positive pole, but are united to it by means of the absorbing attraction of the silver sponge, which incorporates them with itself with such rapidity, in the measure that it iequires them, that not even intense discharges succeed in discovering fatigue in the accumulator, which always works with the external surface of its electrodes, and which admits without any deterioration discharges in short circuit.

Having now described my I claim 18 :7

1. A secondary battery or accumulator in which the electrolyte consists of a solution of chloride of zinc copulatively mixed with another halogen salt of the same metal and of a character having less chemical heat of formation than that of the chloride.

2. A secondary battery or accumulator in which the electrolyte consists of a solution of chloride of'zinc copulatively mixed with zinc bromide. 3. A secondary battery or accumulator in which the electrolyte consists of a solution of chloride of zinc copulatively mixed with another halogen salt of the same metal and of a character having less chemical heat of formation than that of the chloride, and containing a small proportion of hydrochloric acid.

4. A-secondary battery'or accumulator of the character set forth 1n claim 1, wherein invention, what the positive electrode comprises an unattackable conductor carrying an active material consisting of finely divided pure silver.

5. A secondary battery or accumulator of the character set forth in claim 1, wherein the positive electrode comprises pure silver sponge united to an unattackable conductor.

6. A secondary battery or accumulator-of the character set forth in claim 1, wherein the positive electrode comprises graphiteand pure silver combined therewith.

7. A secondary battery includinga negative electrode of, zinc, a positive electrode comprising-an unattackable conductor carr ing an active material consisting of finely ivided pure silver, and an electrolyte consisting of a solution of chloride of zinc copu latlvely mixed with a halogen salt of the same metal.

8. A secondary battery including a negative electrode of zinc, a positive electrode comprising an unattackable conductor car ing an active material consisting of fin l y divided pure silver, and an electrolyte consisting of a solution of chloride of zinc copulatively mixed with zinc bromide.

9. A secondary battery including a negative electrode of zinc, a positive electrode comprising an unattackable conductor carrying an active material consisting of sponge silver, and an electrolyte consistin of a solution of chloride of zinc copu ativel mixed with a halogen salt of the same meta I 10. A secondary battery including a negative electrode of zinc, a positive electrode comprising an unattackable conductor carrying an active material consisting of sponge si ver, and an electrolyte consisting of a solution of chloride of zinc copulatively mixed with zinc bromide.

In testimony whereof I affix my signature.

- EDMUNDO ALMEIDA SALAZAR. 

